Valve-gear for steam-engines.



No. 721,620. I PATENTED FEB. 24, 1903. J. T. THOMPSON.

VALVE GEAR FOR STEAM ENGINES APPLIGATION FILED JUNE 3, 1902.

2 SHEETSSHEET 1 N0 MODEL.

No. 721,620. PATENTED FEB. 24,1903. I J. T. THOMPSON. V w VALVE GEAR FOR STEAM ENGINES.

APPLICATION FILED JUNE 3, 1902. no MODEL. 2 SHBBTFBHEET 2 V 3: I S k) k l'i'fii z 1 Hm I I Swan akkwneg- I UNIT D STATES P -T NT; OFFICE.

JAMES THEODORE THOMPSON, SPRINGFIELD, ILLINOIS.

VALVE-G EAR FOR STEAM-ENGINES.

SPECIFICATION formingpart of Letters Patent N 0. 721,620, dated February 24,1903. Application filed June 3, 1902. Serial No. 110,083. (No model.)

To all whom it may concern.-

Be it known, that I, JAMES THEODORE THOMPSON, a citizen of the United States, residing at Springfield, in the county of Sangawon and State of Illinois, have'invented certain new and useful Improvements in Valve- Gears for Steam-Engines, of which the following is a specification.' p

My invention relates to valve-gears for steam-engines, and has for its object to provide a gearing for locomotive andother engines that will operate the valve directly from the cross-head of the enginewithout the use of the eccentrics usuallyemployed, and thus economize in the cost of manufacture and by reducing the number of workingparts save much of the friction incidental to the complicated machinery usually required to regulate the valves.

Additional ad vantages of my invention will appear hereinafter and by reference to the accompanying drawings, in which- Figure 1 is a side view in elevation of my invention, showing it applied to a locomotive driving mechanism; Fig. 2, areverse View of Fig. 1; Fig. 3, an end view; Fig. 4:, a detail of the slotted link for operating the valve,

and Fig. 5 a view of the pivoted arm.

Referring to the drawings, in which similar reference characters indicate corresponding parts throughout the several views, A indicates an ordinary construction of cylinder; B, a valve-chest containing the ordinary construction of slide-valve; O, the cross-head; D, the guides therefor, and E the drivingrods connecting the cross-head O with the crank-pin F on the locomotive or other driving-wheel G.

My valve-gear consists of the following structure: 1 represents a plate suspended beneath the guides D by means of rods 2, se-

cured to said guides- 3 represents an arm' pivoted to said plate 1 by means of pin 4 and having a'slot 5 inits' free end to receive a pin 6 on the cross-head 0. It will be understood from this descriptionof parts that the arm 3 swings with the motion of the crosshead.

7 represents a block secured to the upper side of guides D and having a pin 8 journaled thereon, one end of said pin having a link 9 keyed thereto, to the free end of which is pivoted the valve-rodlO. On the other end. of pin 8 is keyed arsegniental block 11, which rides in a segmental slot 12 in-link 12, mounted thereon, said link 12 having its lower end extended and slot-ted, as shown at 12", to receive a pin 13, secured to arm 3, said arm 3 being provided with a inultiplicity of holes 14 to provide for adjustment of the pin 13. It'will be"understo'od from this description of the structure of link 12 and its connections that as the arm 3"swings,"actuated by the cross-head O, the link 12 also swings on pin 8 as a pivot, carrying with it the segmental block 11, thus oscillating the pin 8 and the link 9 and giving the valverod 10 a reciprocating motion, which is in turn imparted to the piston in the valve-chamber B. p

In order to adjust the valve-piston in'the proper position to admit the steam on the side of the piston in theicylinder A desired to drive the engine in the proper'direction, either forward or back, before admitting the steam,

I provide a lever-arm 15,;having the ordinary construction" of spring-catch 16, working in notches in quadrant 17.

18 representsthe reach-rod, connecting thelever-arm 15 with .the lever 19, keyed to the shaft 20, jouriialed; in aboxing 21 on the frame of the machine,-aud 22 a swinging arm keyed to shaft 20 and pivotally connected to link 22, which" isin turn pivoted to a plate 23, secured to' the slotted link 12.

24 represents a. rod connecting the arm 3 with a suitable indicator in the locomotivecab'to enable the engineer to know the position of the arm and theconsequent positionof the crank-pin F and'the piston in the cylinder A, so that he may know which way to swing the lever should he want to reverse his engine. It will be understood from this construction that,while the engine is at rest,by the engineer swinging the lever 15 in the proper direction the link 12 may be raised or lowered and shift the. valve in the desired direction. The link 12 being raised or lowered in'thedirection of the 'pins 8 and-13, the segmental slot 12 therein will twist the segmental block 11 and move the valve to the position desired. After the engine is in 'motion-the-lever-arm 15 is moved back to the center of the quadrant, so that the block 11 is in the center of the segmental slot l2 -whi'le the engine is in motion. After the engine has stopped and it is desired to have it start again in the same direction it is only necessary to admit steam again to the cylinder, the shifting of the lever 15 being necessary only when it is desired to reverse the direction of the engine to move it from rest.

I have shown my invention applied to a locomotive; but it will be readily understood that it is equally applicable to engines of other types, and I do not, therefore, wish to be confined to use on a locomotive-engine.

Having thus described my invention, what I claim is 1. In a valve-gear, an oscillating slotted link, a pin suitably journaled, a block secured to one end of said pin to ride in said slotted link, an arm keyed to the other end of said pin and pivoted to the valve-rod, and means to oscillate the link, substantially as shown and described.

2. In a valvegear, an arm oscillated by the cross-head of an engine, a slotted link pivoted to swing with said oscillating arm, a pin suitably journaled, a block secured to one end of said pin to ride in said slotted link, and an arm keyed to the other end of said pin pivoted to the valve-rod, substantially as shown and described.

3. In a valve-gear, a slotted link, a pin suitablyjournaled, a block secured to one end of said pin to ride in said slotted link, an arm keyed to the other end of said pin and pivoted to the valve-rod, means to oscillate said slotted link, and means to vertically adjust said link, substantially as shown and described.

4. In a valve-gear, a slotted link directly connected with the valve-piston, connections between said link and the cross-head of the engine to cause said link to oscillate, and connections between the link and reverse-1e ver of the engine to vertically adjust the link' and actuate the valve-piston, substantially as shown and described.

5. In a valve-gear, an arm pivoted to swing with the cross-head of the engine, a link having a segmental slot therein, means to cause said link to swing with said arm, a pin suitably j ournaled, a block secured to one end of said pin to ride in said segmental slot, and an arm keyed to the other end of said pin and pivoted to the valve-rod, substantially as shown and described.

6. In a valve-gear, a plate suspended beneath the cross-head guides, an arm pivoted to said plate and adapted to swing with the cross-head, a slotted link adapted to oscillate with said swinging arm, and connections be tween said slotted link and the engine valve piston, substantially as shown and described.

7. In a valve-gear, a plate suspended beneath the cross-head guides, an arm pivoted on said plate and adapted to swing with the cross-head of the engine, a link having a segmental slot and a straight slot, said link connected to said arm through said straight slot, a segmental block slidably mounted in said segmental slot, and connections between said block and the valve-piston, substantially as shown and described.

8. In a valve-gear, an arm pivoted to swing with the cross-head of the engine, a link connected to said arm, said link having a segmental slot therein, a pin journaled adjacent to said link, a segmental block keyed to said pin slidably mounted in said slot, an arm keyed to said pin, and the valve-rod pivoted to the free end of said arm, substantially as shown and described.

9. A valve-gear comprising a plate suspended beneath the cross-head guides, an arm pivoted to said plate and having its free end slotted, a pin on the cross-head of the engine to fit into said slot, a block secured to the top of said guides, a pin journaled in said block, a segmental block keyed to said pin, a link having a segmental slot to receive said segmental block and a straight slot, a pin to connect said link with said arm through said straight slot, an arm keyed to said pin connected with the valve-piston, and connections between said slotted link and the reverse-lever to raise and lower said link and shift said valve-piston when the engine is at rest, substantially as shown and described.

In testimony whereof I hereto affix my signature in the presence of two witnesses.

JAMES THEODORE THOMPSON. Witnesses:

ROBERT H. PATTON,- E. J. DUNN. 

